Acetone is produced in a number of ways most of which result in an acetone solution having additional undesirable by-products or impurities. For example, acetone can be produced together with phenol during the decomposition of cumene hydroperoxide. In such example, the decomposition products are fed into a fractionation column, in which the products are separated into a crude acetone solution and a crude phenol solution.
Crude acetone generally contains aldehyde impurities that must be removed to produce a purified acetone solution. Various methods exist for purifying acetone, but each has their disadvantages. For example, crude acetone can be treated by using simple distillation. However, a distillation method alone is not completely effective because impurities, specifically, aliphatic aldehydes, olefins, and a whole series of other impurities, remain in the treated acetone product, reducing its purity and quality.
Another known method of purifying acetone involves distilling crude acetone in two separate columns. In such method, the low molecular weight impurities are isolated in the first rectification column with the addition of an alkaline reagent to the first column. The remaining mixture is fed to the second rectification column to separate high molecular weight impurities, producing commercial acetone. However, such method requires the second rectification column to operate at pressures below atmospheric pressure, which significantly increases operating costs and reduces the productivity of the second column compared to a column operated at atmospheric pressure.
There is a need to provide a simple and cost effective method for removing impurities from crude acetone without sacrificing the purity of the treated acetone.